1 To subjoin, annex, or add at the close or end; to append to; to fix to any part of; as, to affix a syllable to a word; to affix a seal to an instrument; to affix one’s name to a writing.
2 To fix or fasten in any way; to attach physically. Should they [caterpillars] affix them to the leaves of a plant improper for their food. Ray.
3 To attach, unite, or connect with; as, names affixed to ideas, or ideas affixed to things; to affix a stigma to a person; to affix ridicule or blame to any one.
4 To fix or fasten figuratively; — with on or upon; as, eyes affixed upon the ground. [Obs.] Spenser.

That which is affixed; an appendage; esp. one or more letters or syllables added at the end of a word; a suffix; a postfix.